I've told both my kids that they will not be allowed to "express" themselves through their appearance until they can first express the given idea in both written and spoken form eloquently. Appearance expression will be forbidden until other forms of expression are mastered. Most kids (amd parents) have it backwards.
Even after they submit their written and oral essays about "the injustice of the world" or their inner angst, anything that permanently alters the body that God gave them is expressedly forbidden.
For instance, purple hair will be OK, as long as they can coherently and persuasively express just what message the purple hair is supposed to convey.
Good for you. Far too many parents won't "parent" their kids.
Applying that standard would all but eliminate this nonsense. Great line (and idea).